Couple things - so you're an out of state investor, and you have picked Boise to buy in. Why?
I would recommend running vacancy at 10%, prop management 10%, cap ex 10% (can depend on the age/condition of the property), repairs/maintenance 10%. Why those percentages? Easy, fairly accurate, and generally conservative. There is a need to be conservative (always) but especially in today's market. Your interest rate estimate is also very low, I'd expect 7-7.5% on an investment property for a 30yr fixed conventional, unless you do an ARM, which I would not recommend for a new investor.
A SFH is generally going to need some sort of rehab to cash flow positive and have a great ROI. You have to be able to add value into the house. 98% of houses on the MLS will not cashflow (you're on your way to figuring this out).
I would expect an ROI of a MINIMUM of 8-10% in a B area, 15% in a C area, that's after ALL expenses/budgeting are paid.
That said MFH generally cash flow more than a SFH as well.
I could swear Boise was one of the more overvalued markets, so I would be especially careful not to pay too high of a price. You will likely see further drops in the next 6months to a year.
Another thing - you don't want to leave a ton of money in the house. You'll be out of capital soon putting 20% down on every investment property. I would say this is ok for the first one, second one, but by the 3rd one you need to be buying undervalued properties if you want your money to go farther.
Screen by using the 1% rule - not perfect but it's still good. Also, rent should basically be double your PITI for the place to cashflow. By your example, putting 50k down, I'd expect to make 10k after PITI, and 5K after all expenses/budgeting is accounted for. That's my personal guidelines for just looking at a property. Generally I want it to do better than that, but those metrics give decent estimates of what you can expect.